Suppose your opponent controls "Stygian Dirge". If you Special Summon "Cockadoodledoo" using the "If there are no monsters on the field, you can Special Summon this card (from your hand) as a Level 3 monster." effect, "Cockadoodledoo" is Special Summoned as a Level 3 monster, but its Level is reduced by 1 because of "Stygian Dirge", so it becomes a Level 2 monster. If you Special Summon "Cockadoodledoo" using the "If your opponent controls a monster and you control no cards, you can Special Summon this card (from your hand) as a Level 4 monster." effect, "Cockadoodledoo" is Special Summoned as a Level 4 monster, but its Level is reduced by 1 because of "Stygian Dirge", so it becomes a Level 3 monster.[4]